Case Studies

Concern: Foodborne Illness

A bartender at a popular restaurant and night spot was placed off work by his personal physician, reportedly due to his recent diagnosis of Hepatitis A. Hepatitis A is most commonly transmitted by the fecal-oral route via contaminated food or drinking water. Common-source (e.g., restaurant, water) outbreaks are typical. Infected individuals are infectious prior to onset of symptoms, roughly 10 days following infection. The risk of infection to coworkers and patrons was of great concern to the owners of the restaurant.


As the Medical Director for the organization, MAS contacted the employee's personal physician to confirm the diagnosis. Brief investigation found evidence of poor personal hygiene habits of the employee. Hepatitis A is a disease that requires reporting to state health departments. In conference with the state health department, based on timing of diagnosis and the employee's job duties, it was determined that Hepatitis A immunoglobulin would be offered to other employees and patrons able to be contacted within 14 days of potential exposure to prevent secondary cases of Hepatitis A.

Intervention/Prevention Strategies

The most important public health reasons for investigating an outbreak are to help guide disease prevention and control strategies. In this case, we worked with local radio and television stations to notify the patrons of this establishment that they should contact the public health department to verify exposure and recommend prophylaxis.

For this hepatitis A event, quick investigation and response prevented any secondary cases. In addition, we found evidence of poor personal hygiene practices in the establishment. During several employee training meetings, improved personal hygiene, especially vigorous hand washing with soap and water, was strongly encouraged for all workers.

Issue: Cancer Cluster

A county government risk manager is contacted by concerned employees that several employees in one of the County's buildings have been diagnosed with cancer. The employees believe that the building environment is the cause of the cancers. The County's risk manager is concerned for the safety of the employees.


MAS was contacted to investigate the cancer cluster and determine if it was safe to allow the employees to remain in the workspace. Following our systematic protocol, the first step was to verify the diagnoses and establish whether or not a cluster existed. We conducted a survey of the building occupants and contacted their physicians to verify diagnoses. We discovered in this process that the occupants had a variety of different types of cancers including breast, thyroid and lung cancer.

It became readily apparent that the perceived cancer cluster was not actually a cluster, because there were a variety of different types of cancer which indicated no common cause. To be able to provide even stronger data, the incidence of cancer in the buildings was found to be lower than the incidence of same types of cancer in the community. Additionally, cancer in general is very common as noted by the American Cancer Society's "Lifetime Probability of Developing Cancer." For instance, a women's lifetime risk of developing cancer is 33%, a man's lifetime risk is 50%.


Effective, credible, risk communication was essential; the perceived risk was great and the employees were very fearful. The analysis revealed no increased risk, but this information needed to be relayed in a sensitive non-condescending manner. During several meetings with the employees the findings were discussed including the rate of malignancies in the building and the community comparison rates. General discussion about the variety of types of cancers, the rates of these cancers in society and know risk factors were relayed. Employees were given the opportunity to question the physicians in private to ensure that all concerns were addressed. Open, clear, effective risk-communication promoted the development of trust by the employees which allowed for successful conclusion of the investigation.

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